Google's advertisement network, which shows ads on Google website (including Youtube and GMail), other search engines, as well as other websites and mobile apps. It is split into the Search Network, which shows text advertisements on search engines, and the Display Network, which shows targeting on a wider variety of websites. Allows targeting based on demographics, search terms, website visitors, similar audiences, etc.

Twitter is a social media website that also sells data and advertisements. Companies and researchers can buy data from particular accounts, coming from certain geographic areas, or about certain topics. Continuous access to various quantities of data can be purchased, or historical data can be purchased one time. A subset of this data is available for free via Twitter's API.<br />Twitter allows companies to target advertisements based on lists of accounts/emails/phone numbers, audiences like known customers or followers of other accounts, website visitors or app users, search queries, interests, devices, geographic area, purchasing behaviors (based on data from data brokers), language, or gender. Users are then shown advertisements, usually in the form of tweets, and advertisers pay based on the number of impressions, clicks, engagements, followers, etc. Twitter operates its advertisement program and sells data in most countries.